The effect of point defect sinks of various types on the radiation-induced decomposition of the solid solution in the Fe-Ni invar

The residual resistivity technique is used to study radiation-induced decomposition in Fe–34.7at.%Ni alloys irradiated with 5 MeV electrons, with different types of sinks for point defects in the form of dislocations and deformation-induced vacancy clusters. It has been found that irradiation at about 300 K results in the formation of vacancy clusters. The dissociation of these clusters during isochronous annealing at temperatures between 350 and 550 K causes freely migrating vacancies and radiation-accelerated ordering in Fe–Ni alloys. As this takes place, two substages of vacancy cluster dissociation are observed, with dissociation energies of 1.2 and 1.5 eV. At temperatures of about 800 K, homogenization of the solid solution occurs. It is shown that the efficiency of dislocation sinks exceeds that of deformation-induced vacancy clusters.